1. Field of the Invention
The present invention relates to a sealing device.
2. Description of the Relevant Art
Computers or electrical devices are sometimes deployed in surroundings exposed to environmental elements. For example, telephone interface devices may be located on telephone poles, in boxes at a roadside, or under a body of water. Such devices are housed inside sealed enclosures to protect sensitive electrical equipment from exposure to contaminants, such as water, insects and dust.
Often many incoming and outgoing cables, such as electrical cables and fiber optic cables, are connected to the sensitive electrical equipment and communicate to the world outside the enclosure. Therefore, some arrangement must be provided around the cables to allow the incoming and outgoing cables to enter and exit the enclosure, without violating the sealed integrity of the enclosure.
FIGS. 1-4 illustrate a cable sealing arrangement in accordance with the background art. FIG. 1 is a view of an upper surface 3 of an enclosure 1 having a plurality of cable sealing devices 2. FIG. 2 is a close-up perspective view of one of the cable sealing devices 2 of FIG. 1. FIG. 3 illustrates a disassembled cable-sealing device 2. FIG. 4 illustrates an assembled cable-sealing device 2, sealing a cable 4.
Each cable-sealing device 2 includes a base 5. The base 5 is attached to, and protrudes upward from, the upper surface 3 of the enclosure 1. The base 5 has first threads 6 formed around an outer periphery thereof An inside of the base 5 includes a first through hole 7, which communicates an interior of the enclosure 1 with the environment surrounding the enclosure 1. A periphery of the first through hole 7 is formed by a continuous tapered inner wall 8, which tapers in a direction opening away from the enclosure 1.
Each cable-sealing device 2 further includes a gasket 9, such as a grommet. An outer profile of the gasket 9 resembles a cork. A continuous tapered outer wall 11 of the gasket 9 is tapered in a direction opening away from the enclosure 1. A second through hole 10 is formed in a center of the gasket 9. A periphery of the second through hole 10 is formed by a continuous straight inner wall 12. The gasket 9 is made of a compressible and resilient material, such as rubber.
Finally, each cable-sealing device 2 includes a cap 13. Outer walls 14 of the cap 13 form a hexagon, like a bolt or nut. An inside of the cap 13 is hollow and provided with second threads 16 around an inner periphery wall. A third through hole 15 is formed in a center of an upper surface of the cap 13 and passes through to an undersurface 18 of the cap 13. The undersurface 18 of the cap 13 forms a boundary wall of the hollow inside of the cap 13.
As illustrated in FIG. 4, the gasket 9 is interposed between the base 5 and the cap 13. The second threads 16 of the cap 13 are engaged to the first threads 6 of the base 5. Clockwise rotation of the cap 14 causes the undersurface 18 of the cap 13 to contact the gasket 9 and forces the gasket 9 further into the first through hole 7 in the base 5.
As the gasket 9 is pushed into the first through hole 7, the tapered outer wall 11 of the gasket 9 contacts with the tapered inner wall 8 of the base 5. The contact causes radial forces tending to close the second through hole 12 in the gasket 9. Therefore, tightening of the cap 13 results in a seal being formed around the cable 4, as well as, a seal being formed between the outer walls 11 of the gasket 9 and the inner walls 8 of the base 5.
The cable sealing device 2 according to the background art performs adequately in sealing a cable port in the enclosure 1. However, other drawbacks exist in the system of the background art. As illustrated in FIG. 1, in order to tighten or loosen the caps 13, a service technician applies a hand wrench 17. The hand wrench 17 engages the outer walls 14 of the cap 13. Therefore, a space must exist between adjacent cable sealing devices 2 to accommodate the hand wrench 17. Accordingly, an area of the upper surface 3 of the enclosure 1 must be made relative large in order to accommodate a desired number of cables 4. Conversely, the number of cables 4 must be limited in order to fit into a desired area for the upper surface 3 of the enclosure 1.